[GRASS-user] Something wrong: Reprojection of raster maps in various platforms: projected coordinates are different

[Markus Neteler]

On Oct 23, 2015 2:22 AM, "Uttam Kumar" <uttamsinha09 at gmail.com> wrote:

...
> GRASS 7.1.svn (SanLuis_Reservoir_LAEA):~ > v.info -g Image_boundary_box
>
> north=823262.924419209
> south=652223.643294404
> east=-167210.022680164
> west=-518209.054236328
> top=0.000000
> bottom=0.000000
>
>
> I should have got this (This is correct):
>
> north:1638674.575
> south:1481984.575
>
> east:1157941.598
> west:817651.598
>
> Any clue, where am I wrong?

You appear to compare the vector bounding box which easily leads to
misleading results in case of a rotated image.
The only correct way is to compare point wise (eg true corner points of the
image scene).

Or generate a binary data/no data raster from a channel using r.mapcalc and
then r.to.vect to make it a vector polygon truly circumscribing the image
which can then be reprojected.

Best
Markus
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